title: Evaluation of enrichment media for improved PCR-based detection of V. cholerae and V. vulnificus from estuarine water and plankton.
abstract: OBJECTIVE
  Pathogenic Vibrio spp., including V. cholerae and V. vulnificus, are commonly found along the estuaries of the south-east United States; however, it is often difficult to recover these species directly from environmental samples. Pre-enrichment assays are commonly used to improve the detection of pathogenic vibrios from environmental sources. Here, we evaluated a novel enrichment procedure using freshly collected and autoclaved natural estuarine water amended with 1% peptone (designated as estuarine peptone water, EPW) and compared it to traditional alkaline peptone water (APW) for detection by PCR of V. cholerae and V. vulnificus.
  
  
  RESULTS
  Of the 50 samples collected in total, V. cholerae DNA was detected in APW 10% of the time and in EPW 40% of the time. Likewise, the cholera toxin gene (ctxA) was detected in 4 vs 18% of the samples using APW and EPW, respectively. Conversely, APW showed improved recovery for V. vulnificus relative to EPW with respective detection frequencies of 46 and 20%. Results showed similar patterns across different sample types (water and plankton).
  
  
  CONCLUSIONS
  While enrichment in traditional APW was adequate for the recovery of Vibrio vulnificius, use of sterile estuarine water amended with peptone significantly improved the detection of V. cholerae and the virulence gene ctxA from estuarine sources.
authors.affiliation: Department of Environmental Health Science, The University of Georgia, Athens, GA 30602, USA.
authors.forename: L
authors.initials: L
authors.lastname: Malayil
authors.forename: J W
authors.initials: JW
authors.lastname: Turner
authors.forename: B L
authors.initials: BL
authors.lastname: Mote
authors.forename: K
authors.initials: K
authors.lastname: Howe
authors.forename: E K
authors.initials: EK
authors.lastname: Lipp
mesh_terms: D002772:Cholera Toxin / Q000235:genetics; D003470:Culture Media / Q000737:chemistry*; D017931:DNA Primers; D004269:DNA, Bacterial / Q000302:isolation & purification; D057230:Limit of Detection; D010461:Peptones / Q000737:chemistry; D010933:Plankton / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012623:Seawater / Q000032:analysis; D014733:Vibrio / Q000235:genetics / Q000302:isolation & purification*; D014871:Water Microbiology
chemical_list: D003470:Culture Media; D017931:DNA Primers; D004269:DNA, Bacterial; D010461:Peptones; D002772:Cholera Toxin